Drive axles operatively connect the transaxle mechanism of a vehicle to the hubs on which the wheels are mounted. The vast majority of drive axles incorporate a male spline which is secured to its mating member by barrel type snap rings. On the other hand, the inboard end on the left hand axle employed with at least automatic shifting transaxles generally utilizes a female spline which installs over a shaft that protrudes from the transaxle housing.
An axle seal is positioned interiorly of the access aperture in the housing of the transaxle, at the entry point of the drive axle assembly. The axle seal retains lubricant within the transaxle housing and prevents unwanted materials in the environment within which the transaxle is operating from entering the transaxle housing. To properly function, the seal must engage the uninterrupted periphery of the axle. Therefore, the seal must remain free of defects and aberrations, particularly at the seal-to-axle interface, if it to function effectively.
Insertion of the drive axle into the transaxle is the most frequent cause of damage to the axle seal. Generally, such damage results when a sharp edge, or burr, on the drive spline of the axle cuts, or even slightly nicks, the seal. Because integrity of the seal is required for its satisfactory operation, any damaged seal must be replaced. The necessity of replacing damaged seals can add to the time, and thus the cost, of the original assembly process. In addition, any maintenance procedure which requires removal of the drive axle, and then replacement thereof, after the vehicle has been assembled subjects the seal to a considerable likelihood of damage. This likelihood is greatly magnified because the mechanic must insert the axle in close quarters and around other vehicular parts which were not on the vehicle when the original drive axle was installed, all without a good view of the access aperture in the transaxle housing through which the drive axle must be inserted.